Mix hum bucket with single coil

[micguy]

It's Physics, adding a coil (inductor) to a RLC circuit will change the resonant frequency.

Me. my Physics degree, and my few decodes worth of audio gear designing agree with this guy. Adding a second coil in series will definitely change your sound- in theory and in practice.

 

[BurtMacklinFBI]

If single coil hum is really that big of an issue it seems to me that it'd be cheaper and more practical to just use a noise gate. An ISP Decimator 2 can be had for pretty cheap on Reverb and does a great job without murdering your tone.

 

[bassbenj]

If hum turns out to be an issue, it's fairly trivial to add a hum cancelling coil in series with the single coil. In theory this changes the tone, but in practice, no, it doesn't. As long as you can find space inside the bass somewhere to cram it in...a similar cheap pickup with the magnet ripped off works nicely.

That said, any split coil (hum cancelling) J pickup will do the trick and be much nicer. Just, if you have some sort of esoteric weird single coil in mind, it's doable too. But yeah don't do that. P or J cutouts leave you with more options.

No, a "dummy coil" hum canceling coil does indeed change the tone. I tried to add one to my SX Fender Jazz bass clone where I had wired a switch that would give you bridge, both or neck pickups. The both position had no coil in the circuit so it kept the same tone. But both the "neck only" and "bridge only" positions switched in dummy coil to cancel hum which it did quite nicely. BUT the added inductance changed the tone so much I eventually just put it all back the single coil way it was. and lived with the hum. About the only way a "dummy coil" works right is if you have an active bass and add it in electronically. Alembics do this and Audere used to have a single coil dummy setup available too, but I don't know if they still sell it.